Puree or blend liver in a food processor or blender. Add oil and blend until all chunks are gone and mixture is smooth. Pour into pan. Bake for 2-3 hours. I usually bake it for 2 hours, which leaves a consistency that is still moist, but doesn't fall apart. The longer you bake it, the drier it will get and the more jerky like it will be. Softer treats work best as the dogs do not have to chew them as much when training. When finished, remove from pan and let cool until you can touch it and work with it. Remove foil and place liver "cake" on a cutting board. Cut into very small pieces. The smaller pieces work best even for big dogs as this recipe is rich and small treats will last longer. Allow the pups to taste test and see the smiles develop! Be sure to refrigerate leftovers and freeze anything you won't use within a week. Happy Training!